Japanese Patent Applications laid open Nos. JP2016-019068A and JP2017-103678A have disclosed amplifier modules operable in radio frequencies (RF). FIG. 6 schematically shows an arrangement of such a high frequency amplifier module. The high frequency amplifier module 100 disclosed therein provides a package 103 and two transistors, 121 and 122, enclosed within the package 103. The package 103, which has a rectangular plane shape, provides terminals, 111 to 113, disposed in one side of the package 103 and other terminals, 114 to 116, in another side of the package 103 facing the former side. The terminal 111 is an input terminal connected with a gate of the first transistor 121 through a capacitor 151 and a matching unit 131; while, a drain of the first transistor 121 is connected with a gate of the second transistor 122 through a capacitor 152 and a matching unit 133. The second transistor 122 in a drain thereof is connected with the terminal 116, which is an output terminal, through a matching unit 134 and a capacitor 153.
The terminal 112, which is coupled with the gate of the first transistor 121 through a resistor 141, supplies a gate bias to the first transistor 121. The terminal 114, which is coupled with the drain of the first transistor 121 through an inductor 161, supplies a drain bias to the first transistor 121. The terminal 113, which is coupled with the gate of the second transistor 122 through a resistor 142 provides a gate bias to the second transistor 122. The terminal 115, which is coupled with the drain of the second transistor 122 through an inductor 162 supplies a drain bias to the second transistor 122.
In the amplifier module 100 shown in FIG. 6, the capacitor 151, the matching unit 131 the transistor 121, the other matching unit 132, and the inductor 161 are disposed on a line connecting two terminals, 111 and 114; while, the resistor 142, the matching unit 133, the second transistor 122, the other matching unit 134, and the capacitor 153 are also disposed on another line connecting two terminals, 113 and 116. Moreover, the former disposition is connected with the latter disposition through the capacitor 152. Thus, the conventional amplifier module 100 shown in FIG. 6 inevitably provides a signal path from the input terminal 111 to the output terminal 116 with a zigzag path, which possibly causes instable performance in the high frequency amplifier 100.